Prior art cameras disclose a number of ways for the camera operator to input information into the camera. For example, U.S. Pat. No. 4,958,181 discloses a camera system having a camera and an external device (IC card 4) detachably mounted on the camera by a holder 5. When the external device is mounted on the camera, they are connected electrically with each other and communicate therebetween in order to read a program or data memorized in the external device into a memory in the camera. The camera is controlled according to the program designated by the external device.
Such an arrangement for inputting information into a camera is less than optimal for several reasons. Extra hardware (i.e. holder 5 and the appropriate electrical connections) is required in the camera, thereby increasing the size and cost of the camera. The camera operator must carry around another type of paraphernalia (i.e. IC card 4) and learn how to properly insert the card into the holder, consequently increasing the complexity of operation of the camera.
Another method of inputting information into a camera is disclosed in commonly-assigned U.S. Pat. No. 5,229,810 (the '810 patent). This patent discloses that a virtually transparent magnetic layer is included as an additional layer in a photographic filmstrip. The magnetic layer must be transparent so that light can be transmitted through the filmstrip when making photographs or viewing slides. Information exchange between various users of the film such as the film manufacturer, the camera user, the dealer and photofinisher is facilitated by plural longitudinal magnetic tracks on the film that begin and end within individual frames. Each track is dedicated to the writing and reading of a predetermined set of parameters relating to the corresponding frame, for easy access by a particular one of the various users. Each user has the capability to read and/or write information in self-identifying data in the corresponding tracks. FIG. 2 discloses a camera with a magnetic read/write head.
In order to make the magnetic layer virtually transparent, it is made extremely thin, and the magnetic particle distribution and size are so designed that the composite granularities of the photographic and magnetic media are matched (see U.S. Pat. No. 3,782,947 to Krall). As a result, information stored on the transparent magnetic layer emits extremely weak magnetic signal levels relative to information stored on conventional video and audio cassette tapes which utilize a conventional opaque magnetic layer. Consequently, data recording and reading with the transparent magnetic layer is not very robust compared with more conventional opaque magnetic recording layers. Therefore, attempting to impart a large amount of data from a transparent magnetic layer of a photographic film to a camera risks data loss.
Additionally, the information density which can be stored and subsequently read to/from a transparent magnetic layer is much less than with conventional opaque magnetic layers. Thus, a much larger area of transparent magnetic material must be used to store the same amount of information which can be stored on a smaller area of conventional opaque magnetic material.